HENGSHAN AiLi Battery Monitor

I’ve always wanted to be able to monitor my RV’s house batteries and know their state of charge (SoC).

While you can estimate SoC by reading the battery voltage, it’s not accurate. There have been battery monitoring devices available for years, but the high cost, usually several hundred dollars, has kept me from buying one. I was thrilled to discover these little AiLi monitors from HENGSHAN, on Amazon, and the low price prompted me to buy a couple.

Simply stated, these devices use a calibrated shunt to measure current flowing to or from the battery bank and keep track of the current state of charge. As you draw power from the battery bank, or recharge it, the monitor keeps track of how much current is flowing in or out over time and computes the SoC in percent. They work with lead-acid and lithium battery systems, and these things are surprisingly accurate! I’ve been testing them for a couple of months and I am amazed at how well they work.

They are easy to install and set up: the main negative cable from the battery bank is removed from the batteries and connected to the shunt. Then, a second cable (supplied by the installer) is connected between the shunt and the battery bank. An additional lightgauge wire is added between a terminal on the shunt and a +12V source. This provides the power to run the meter head. The shunt may be placed in the battery compartment, as it has no active components on it, and it isn’t a potential spark source. The provided data cable (about 16-ft. long!) connects the shunt to the meter head, which can then be mounted in a convenient location. After making sure that amperage and voltage are being measured and displayed, a simple calibration step synchronizes the device with your battery bank, and no other recurring calibration is needed. There are two versions.

100A—Small Display
The 100/350-amp version has a small round display that shows SoC, and there are buttons to allow you to access amperage, wattage and voltage displays. Available with either a 100A or 350A shunt. The smaller unit is under $50 and may be found on Amazon, eBay and other online retailers.

500A—Large Display
The 500A version has a larger display panel, and it displays SoC, amps, volts, watts and time all together on one screen with no buttons to push. I prefer the larger display, but it is a bit more expensive. The larger unit, with a 500A shunt, is under $80 and may be found on Amazon, eBay and other online retailers.

Regardless which you prefer, it’s a great inexpensive tool to help you keep track of your battery bank and charging systems!

Complete Product Name: HENGSHAN AiLi Battery Monitor

Company Name and Info: HENGSHAN AiLi

Online Shopping Links: 100A - Small Display - https://amzn.to/3OCFB06 | 500A Large display - https://amzn.to/3PuV0Rz |

Average Street Price: $50-$80

Original Publication Date: MJ/22